Bt eggplant has only been grown in a limited amount since 2014 so documentation on insecticide reductions is being developed but one report indicated a 74% reduction. Bt corn and Bt cotton have been grown since 1996 and the reduction in insecticide use has been dramatic with a 48% reduction in corn and a 26% reduction in cotton (Barfoot and Brookes 2014)
Frequently Asked Questions
A review of the environmental safety of Cry1Ab can be found at http://www.ilsi.org/ResearchFoundation/CERA/Publications/cry1ab_en.pdf The cry1-Ac protein is highly specific to caterpillar pests and does not adversely affect non-target organisms (invertebrates and vertebrates including birds, mammals and human), because they do not have the requisite receptor proteins found in the mid-gut of target insects. The protocol adopted for testing Bt brinjal specifically aimed to assess the effect of Bt brinjal on non-target pests (sucking pests and secondary caterpillars) and beneficial insects on brinjal. Non-target insect pests include leaf roller Epilachna beetle, grey weevil, root grub, and sucking pests, leafhoppers, thrips, whiteflies and mites. The vast data collected over many years of field trials conducted at various locations showed that non-target sucking pest counts did not vary significantly among Bt and non-Bt brinjal plants.
A review of the environmental safety of Cry1Ab can be found at http://www.ilsi.org/ResearchFoundation/CERA/Publications/cry1ab_en.pdf Field trial data demonstrate that Bt brinjal event EE-1, expressing the cry1-Ac protein, does not have any significant effect on soil micro flora (both fungi and bacteria), and soil invertebrates such as earthworm, collembola and nematodes. This is in agreement with numerous published studies that have shown that B. thuringiensis and Bt proteins act specifically on target insect pests and that they do not have any deleterious effect on non-target organisms. No cry1-Ac protein was detected in any of the soil samples from Bt brinjal field plots, which demonstrates that the protein is rapidly degraded. In fact, because the cry1-Ac gene was derived from a common soil bacterium it is therefore expected that soil micro-organisms are already routinely exposed to these proteins within the natural environment.
Bt brinjal has been developed by the Bangladesh Agricultural Research Institute (BARI) in an international public private partnership involving a consortium managed by Cornell University through the Agricultural Biotechnology Support Project II (ABSPII). The Maharashtra Hybrid Seeds Company Ltd. (Mahyco) donated brinjal Bt technology to BARI.
There is no effective counter to pests such as the fruit and shoot borer in organic cultivation of brinjal. Most available methods fall far short of effective goals at pest control and are labour and resource intensive, rendering them impractical and prohibitive. Bt brinjal, on the other hand, uses a gene from a naturally occurring soil bacterium to produce a protein that effectively combats the fruit and shoot borer, significantly reducing or even eliminating pesticide usage for this pest. This is a major step towards the stated goal of organic cultivation.
There is no truth in this statement. Bt brinjal will be available as open pollinated varieties that will reach the farmers at low cost through a public distribution system by the various agricultural universities and research institutions involved in the project. These varieties will be qualitatively the same as existing varieties currently grown by the farmers apart from immunity to FSB. Farmers can save seeds from their harvest for planting future generations, and indeed will be encouraged to do so. For hybrids, as is the case currently for non-Bt brinjal (and indeed any hybrid cultivated crop), the farmers do indeed source fresh seeds from the private sector year after year. This is because hybrid varieties do not breed true, so second-generation plants do not have hybrid advantages and are less useful for planting.
Bt brinjal seeds in Bangladesh are currently distributed for free. Seeds are made available to the farmers through the public sector seed distribution system. BARI is producing the seed of Bt brinjal in its seed production center.
Most insecticide sprays kill more than just the target pest and often kill beneficial insects, including pollinators, and other animals. Evidence from Bt crops grown in other countries has shown a greater biodiversity of insects when such spraying is reduced. Bt brinjal targets the fruit and shoot borer. It does not affect non-target or beneficial insects.
Because Bt brinjal will significantly reduce the need for insecticides, use of the new variety will lead to lower levels of insecticide residues in the soil and groundwater (Shelton et al 2002). This would offer significant environmental improvement.
The centre of origin for brinjal is not clear. However, the maximum varietal distribution of brinjal may be observed in South and South East Asia. Researchers have studied brinjal crossing behaviour and Bt brinjal behaves in a similar fashion. It does not show any changes in its pollen dispersal or crossability than has been reported in conventional brinjal. As the cry1-Ac gene does not confer any change in plant habit or behaviour, it will have no impact on diversity.
Field tests have shown that there are no adverse effects resulting from pollen transfer from Bt brinjal to other plants because of genetic incompatibility.
Bt brinjal is specifically targeted against the fruit and shoot borer and related pests in brinjal such as the fruit borer and stem borer. As such it is ineffective against other insects. This helps ensure that beneficial insects and organisms continue to thrive and are not affected as usually occurs in the case of pesticide sprays.
Bt brinjal looks and has the same nutrient composition as the conventional brinjal except for the additional Bt protein that renders it resistant to the fruit and shoot borer. It retains the same nutritional value as non-Bt brinjal and feeding tests with different animal groups that included fish, chicken, rabbit, goat, rats and buffalo revealed no toxicity or new allergenic compounds. Bt brinjal is likely to be lower in pesticide residues, and therefore healthier, than conventional brinjal grown with regular applications of toxic insecticides.
Scientists and economists consortium anticipate the following benefits to farmers:
- When used in conjunction with good farming practices, Bt brinjal crops will produce more undamaged fruit than non-bioengineered brinjal crops. Higher yields will lead to increased income for farmers.
- As the Bt brinjal will require fewer insecticidal sprays, farmer and farm workers’ exposure to insecticides will be minimized.
- The pricing of varieties distributed through the public system will be based on a cost-recovery model that aims to bring high quality seeds to economically weaker farming communities in the region.
- Farmers will be able to continue the practice they currently follow for varieties and for hybrids.
Bacillus thuringiensis microbial formulations have been shown to be very specific to target insect pests. Tests have shown that Bt brinjal’s effectiveness is 100% pest mortality in shoots and fruits, compared to 30% or less with conventional pesticide treated varieties.
Conventional insecticides are generally sprayed on the crops to destroy pests. The shortfalls in this system are many. Insecticidal sprays are effective only during a brief window between the hatching of larvae and its penetration into the fruit and shoot of the plant. Once the larva bores into the plant, it is impervious to insecticidal sprays. To avoid this possibility, farmers tend to resort to saturation spraying, a process that not only adversely affects the environment, but also their health and that of the end consumers. These sprays also destroy non-target insects and organisms that are otherwise beneficial to agricultural plants and the local ecology. In Bt brinjal, the insecticidal protein is expressed by the plant itself and the borer is killed as it tries to bore into the plant. However, Bt brinjal is harmless to the beneficial insects and non-target organisms.
Currently, farmers use labour-intensive practices to control FSB such as the prompt manual removal of wilted shoots. The trapping of male moths using pheromones to prevent mating and the use of nylon netting is also done to protect the plants. These efforts are usually insufficient, thereby forcing farmers to rely heavily on insecticide sprays to control FSB. However, FSB is only vulnerable to sprays for a few hours before it bores into the plant, forcing farmers to spray insecticides as often as every 2-3 days. Intensive use of insecticides poses a serious threat to human health and the environment. Heavy use of pesticide sprays also adds to the cost of production. With Bt brinjal, the farmers will gain increased productivity, profits and health benefits while the consumers will get access to pesticide-free safer fruits. The increased productivity will help to maintain low prices for the consumer while the farmers will gain from higher marketable yields.
Brinjal is a primary source of cash income for resource-poor farmers in Bangladesh. Currently, 7.8 percent of the land under vegetable crops, 64,208, hectares is dedicated to growing about 340,000 metric tones of brinjal per annum. However, this is only 1.1 percent of the world’s production. Brinjal crop productivity is lower in Bangladesh than in neighboring countries. The main growing districts are: Bogra, Chittagong, Comilla, Dhaka, Dinajpur, Faridpur, Jamalpur, Jessore, Khagrachari, Khulna, Mymensingh, Rangamati, Rangpur, Rajshahi, Sylhet, and Tangail.
Consumers in many countries have been consuming Bt crops, or products derived from them, since they were first commercialized in 1996. For example, about 30% of the world’s production of corn is protected from insect attack by a Bt protein very similar to the one in Bt eggplant.
Genetic engineering involves the introduction of a specific gene into the genome of a plant to obtain a desired trait. The gene introduced may come from another plant species or from any other organism. While traditional plant breeding involves crossing related plants, genetic engineering uses modern biotechnology tools that allow breeders to be more precise and enables the introduction of useful traits that are otherwise difficult or impossible to achieve by conventional means. The goals of genetic engineering are the same as with traditional breeding. Scientists may aim to improve crop performance in the field by conferring pest and disease resistance, herbicide resistance, or tolerance to environmental stresses (such as salinity and drought or flooding). They may also aim to develop products with enhanced value, such as improved post-harvest life, nutritional value, or other health benefits.
FSBR-brinjal refers to “fruit and shoot borer resistant” brinjal, which is also called Bt brinjal, and is brinjal that was evolved through genetic engineering. Brinjal is also known as eggplant or aubergine around the world. Contrary to popular misconception, the “Bt” in Bt brinjal does not stand for “Biotechnology”. It is actually short for Bacillus thuringiensis, a soil bacterium that harbours a gene called cry1-Ac. The cry1-Ac gene produces an insecticidal protein that is effective in controlling the larvae of certain moths that bore into and feed on the shoots, leaves and fruit of plants like brinjal. This protein is toxic to a narrow range of insects, but is not harmful to animals or humans. In the last few years, several crops have been genetically engineered to produce their own Bt proteins, making them resistant to specific groups of insects. Bt brinjal is genetically engineered to contain its own FSB resistance mechanism − the Bt gene, cry1-Ac.
Bt brinjal provides an effective environmentally friendly and economically sustainable solution to tackle crop losses resulting from fruit and shoot borer infestation. The cry1-Ac protein produced in Bt brinjal is similar in structure and activity to that found in nature and is already available and used commercially in the form of Bt-based biopesticides, often used by organic growers. However, pesticidal sprays are only effective during a brief window then the larvae hatches from the egg and bores into the fruit or shoot of the brinjal plant. Once the larvae takes refuge within the fruit they are safe from surface sprays however intensive they may be, and are free to destroy the crop from within. Bt brinjal, in which the cry1-Ac gene is genetically engineered into the brinjal, ensures a built-in resistance against the fruit and shoot borer larvae (see Box 2 to learn why brinjal was chosen to be the first genetically engineered food crop in Bangladesh).
The experience of millions of consumers of Bt products for nearly 20 years and the use of Bt as a biopesticide for more than 80 years indicates an excellent track record of safety to humans and the environment. Scientists have conducted rigorous tests as per the stringent requirements of regulatory bodies to ensure that Bt brinjal is safe for human consumption.
- Nutritional content: Bt brinjal is compositionally identical to conventional brinjal except for the additional Bt protein. It therefore has the same nutritional value as non-Bt brinjal.
- Toxicity: Bt brinjal has been tested on a number of different animal groups to show that it is not toxic to any group. These include, but are not limited to, fish, chicken, rabbit, goat, rats and buffalo. These studies have confirmed the long history of food safety of the cry1-Ac protein to animals and humans.
- Allergenicity: The Bt brinjal has been tested to ascertain that it contains no new allergenic compounds and it is found to be non-allergenic.